When attacked by some college students, Hitomi kills all of them except Yūya, who is shocked to see her transform into a beast and battle a lion monster at an abandoned waste facility. These strange people are "Brutes", fighters that have been created to combine the brains of humans and the fangs of beasts. The "Killing Bites" battles have been the decisive turning points in the Japanese economy since ancient times. Hitomi is assigned to protect Yūya.
